In the past, switches or other elements of a communication (or telecommunication) network that route calls from one location to another, governed and provided special telecommunications services. Such switches or other elements are usually at least part of a “serving system” that provides service for multiple subscribers (typically in a given area). In a wireless intelligent network (WIN), each serving system includes a switch often referred to as a mobile switching center (MSC) as well as a signal transfer point (STP) and a service control point (SCP). STPs are the packet switches of the network which receive and route incoming signaling information towards the proper destination, and perform other routing functions. SCPs are databases that provide information necessary for advanced call-processing capabilities. The serving system also includes a home location register (HLR) that defines the services and features authorized for use by the subscriber.
A mobile subscriber communicates with the MSC through a base station, which provides an air interface for the mobile subscriber. The MSC connects to the HLR and the SCP through the signaling system 7 (SS7) and STP networks in order to access information about the subscriber. When a mobile subscriber operates in a given serving system, the serving system engages in signaling communication with the HLR in the subscriber's home system to notify the HLR where the subscriber is located and to obtain the subscriber's current profile. The serving system may also include a subscriber profile database referred to as a visitor location register (VLR), which stores a temporary copy of a subscriber's profile obtained from the HLR. The MSC may also access the VLR to obtain information about the subscriber.
For a prepaid cellular telephone, the subscriber has an account with a prepaid cellular phone company. The subscriber may use the cellular telephone as long as there are sufficient funds in his or her account. To add additional funds to or “top-up” his/her account, the subscriber must call a customer service number, typically an 800 number, and provide calling card or credit card information to the customer service representative. The cost for placing this call is paid by the prepaid cellular phone company and passed on to the subscriber. Thus the subscriber does not get the full benefit of the available funds for making phone calls. This can become a burdensome and an inefficient manner of providing top-up services. Additionally, if the subscriber wishes to purchase an item using the prepaid cellular phone, the subscriber is charged for the phone call.